An internal inquiry concluded that training of new recruits to the NHS helpline was "not fit for purpose", while underqualified recruits were being used as "stop-gaps" to cover shifts due to staff shortages.

The report by South Central Ambulance Service into concerns raised by a Telegraph investigation last year found that the time spent on coaching call handlers at its call centre fell short of NHS guidance after being "condensed" by the centre's manager.

In one case our reporter was unable to send a crew to a man suffering from chest pains, because he could not be sure about the cause of his symptoms. The computer’s decision was upheld by a medic at the centre and the man was told he would be contacted by a GP instead.

The ambulance service's report attempted to blame the reporter for the incident. However it admitted that there was "a lack of suitable and adequate governance" at the time in May and June 2015.

The reporter did not have a dedicated coach, leading to "inconsistent messages and confusion".

"From a patient safety point of view this practice must be a risk as the service is relying on inexperienced staff, who have not yet qualified as solo operators, to cover shifts, usually of high demand," the report concluded.

A separate report by the Care Quality Commission said SCAS denied any of the problems identified by the Telegraph compromised the "safety" of the service. But the trust acknowledged that "issues had been identified during the course of the investigation which did give cause for concern". There had been "an increase of coaching and supervision" following the investigation